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ColumnFixedString: better 'replicate' method [#CLICKHOUSE-2877].

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This commit is contained in:
Alexey Milovidov 2017-03-11 04:12:14 +03:00
parent 93a930859e
commit 2d6d90a2cc
1 changed files with 4 additions and 10 deletions
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14
dbms/src/Columns/ColumnFixedString.cpp
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@ -211,18 +211,12 @@ ColumnPtr ColumnFixedString::replicate(const Offsets_t & offsets) const
return res;
Chars_t & res_chars = res->chars;
res_chars.reserve(n * offsets.back());
res_chars.resize(n * offsets.back());
Offset_t prev_offset = 0;
Offset_t curr_offset = 0;
for (size_t i = 0; i < col_size; ++i)
{
size_t size_to_replicate = offsets[i] - prev_offset;
prev_offset = offsets[i];
for (size_t j = 0; j < size_to_replicate; ++j)
for (size_t k = 0; k < n; ++k)
res_chars.push_back(chars[i * n + k]);
}
for (size_t next_offset = offsets[i]; curr_offset < next_offset; ++curr_offset)
memcpySmallAllowReadWriteOverflow15(&res->chars[curr_offset * n], &chars[i * n], n);
return res;
}